Can I access Terminal from Single User Mode?

So I have an early 2011 MBP that is having the graphics switiching problem that's been well documented in some other threads recently:
https://discussions.apple.com/thread/4766577?start=120&tstart=0
http://appleinsider.com/articles/13/10/14/apples-2011-macbook-pro-lineup-sufferi ng-from-sporadic-gpu-failures
Basically, I cannot boot because it goes to a white screen after the apple logo.
I found these terminal commands that will shut off the discrete graphics card so that only the integrated graphics will run, which would be an ok solution because I mainly use the computer for Recording/Mixing etc with Logic Pro, so I don't really need the more powerful graphics.
http://forums.appleinsider.com/t/160161/apples-2011-macbook-pro-lineup-suffering -from-sporadic-gpu-failures/80#post_2420378
But I of course can't access Terminal because I can't get past startup. Is there a way to get to terminal and/or enter these commands while in Single User Mode?

Are you referring to these
You can move the kext out with these commands:
> mkdir DisabledExtensions
> cd /System/Library/Extensions
> sudo mv ATIRadeonX****.kext ~/DisabledExtensions (replace asterisks with your model's numbers)
> sudo touch /System/Library/Extensions
If so there is nothing to take, the commands are physically removing system files. Once those files are moved there is no way for them to go back unless you put them back or you do an install of the OS.
But I am surprised that Safe mode does not work for you. In Safe mode the system only uses the onboard graphics. Are you certain you ere booted into Safe mode? When in Safe mode the words Safe Boot will appear in red letters at the top of the login screen. Did you see that? I ask because it is easy to mistime the Shift key press during boot and not actually get into Safe mode.
Perhaps you problem something different?

Similar Messages

Powerbook -can't start up in single user mode or from CD-why?

My daughter was gifted a Powerbook (15"). I've upgraded it to 10.5.8. It has enough speed, (1.67 Ghz), 2 gigs RAM- but it is a sticky little machine- it freezes a lot. Froze twice during the upgrade, froze once during login, Froze once while trying to do a software update, froze once while trying to get into the system preferences. It freezes pretty consistently after 15-30 minutes or so, no matter what it's doing -if a program is running or not. I tried downloading AppleJack to run a diagnostic. That requires starting up from single user mode. I tried to do that , but the machine just opens to the login screen. I also tried running TechTool from the CD, and the machine wouldn't start up from CD either. What should I try next?

Try this one for some information.

IMac G5 won't boot in normal and safe mode, but will from single-user mode

Hello everyone,
I'm quite new here, so I try to do my best if you have a question.
Yesterday, someone nearby me had a iMac G5 (Powermac8,1), and he sayd, that the computer sometimes will boot, sometimes not.
I did test it, I thought it was running fine, but when I played some music in iTunes, it was stuck on 9 seconds, and crashed (with a kernel panic). The guy also sayd, that there was nothing important on the computer, so a clean install was fine.
Now, the problem is, that it will not boot in normal mode (without anything pressed on boot), also it won't in safe mode (shift-boot), but it will, when I enter single-user mode, mount the hard drive and exit from single-user mode so it will go futher on booting. Sometimes it will not, and immediately gives you a kernel panic in single-user mode, but it will 90 percent of the time.
Then you've got another problem: when it's running in the normal desktop from single-user mode, it'll be stuck after some time again. If I look into the Kernel Panic file created, most times it's because of Spotlight indexing, so I disabled that.
He also gave me the disks (Apple Hardware Test and Extra Applications, and iMac G5 Mac OS X Install Disks 1-3) that came with the Mac. He sayd that I could use them, but I think he didn't test out the SuperDrive, because when I insert a disk, it will try to read, but it will make 2 same sounds, and quits after 10 tries, when it will spit the cd out. Also normal (audio) disks.
Also, I must hurry with the commands for mounting and exiting in single-user mode, or it will just not boot.
In all cases, after 30-45 seconds from pressing the power button, the fan will start blowing at full speed, and it will stop after the exit command in Single-user mode. That's weird.
I can't do anything with the SuperDrive, I can't normally boot in Mac OS X except for Single-user mode (but I don't think he would like to do that every time the computer boots up), and I have very limited time when Mac OS X arrived on the desktop.
When booting in Verbose mode, it will be stuck on this:
AppleSMU::PMU vers = 0x000d004c, SPU vers = 0x15, SDB vers = 0x01,
(and sometimes ends with a kernel crash by fsck_hfs)
Things I've tried (without any success):
- /sbin/fsck -fy (in single-user mode)
- Disabling Spotlight and mds
If you want some more information, feel free to ask!
Greetings
-MrYoranimo
PS: My main language is Dutch, so my English can be bad at some points.

Thank you for your support! This reply is a little bit late, because I was to the camping this weekend.
The only thing I sure do know, is that the iMac has a bad SuperDrive. That's one problem, but I don't really wanna use it, and you fix everything by Single-user mode and when I get to the desktop to test things and change stuff in the Preference Panes.
What also came to my mind was that there also is a problem with the videocard (driver), because sometimes when I boot into Single-user mode, I can see some white pixels which aren't supposed to be there. And when booting from SUM you can see that some of the colors are different and there are weird patterns on the screen.
I also tried to setup a NetBoot server on this computer (MacBook Mid 2010) with just Lion 10.7.4 on it, but I'm not that expert and I didn't really find the good posts on the Internet, although I tried it with the Server applications and both Server applications and DeployStudio. But I didn't succeed.
I don't really like buying a new FireWire hard disk or external FireWire dvd reader/writer, except if it has USB support, because my MacBook doesn't support FireWire, and I really wanna make use of it then.
If I know more or have fixed it, I will surely post again here with what I did to fix it (if no one else has posted here already ).

Repairing disk permissions from single user mode

I accidentally changed the disk permissions on my Macintosh HD to "none" for everyone, except system and admin, who both still have read/write/exec privileges. Now, my Mac won't boot up. What can I do to fix this from single user mode or verbose mode?

Hi,
if you reboot your mac and press Command -R you can start in recovery mode and repair the permissions.
here you can find how to proceed http://support.apple.com/kb/HT4718

Saving from Single User Mode???

ok, so my computer *****, and i just want to reformat the drive and start from scratchville.
is there any way to have a USB Thumbdrive or external hard drive attached and move files from single user mode to the thumb drive to store it. and then once i get my system disk reformat or reinstall the operating system.
i cannot login to my computer any other way besides single user. i have run FSCK and nothing.
all im trying to do is move files so i dont have to worry about losing all of my music, photos, and documents.

WeeManG4:
i cannot login to my computer any other way besides single user.
Have you tried Firewire Target Disk Mode?
cornelius

I installed Firefox on laptop under Admin acct--now I can't access it from std user account

I installed Firefox on a laptop under Admin acct--now I can't access it from std user account. If I installed Firefox onto the laptop under the Admin account, why didn't it put a desktop icon on the std user account also? I don't recall ever having this problem on an any other computer I've had. I have already tried looking under the program files folders for a Mozilla folder while logged into the std user account-- there is no Mozilla folder to be found. Also, when I try to install Firefox on the Std user account, the parental controls keeps me from doing it. I have went in and added the Firefox install web link as an allowable website under the parental controls, but it does not help. Please help me figure out how to get Firefox installed on my std user account.

Check the date and time in the clock on your computer: (double) click the clock icon on the Windows Taskbar.
Check out why the site is untrusted and click "Technical Details to expand this section.<br>If the certificate is not trusted because no issuer chain was provided (sec_error_unknown_issuer) then see if you can install this intermediate certificate from another source.
You can retrieve the certificate and check details like who issued certificates and expiration dates of certificates.
*Click the link at the bottom of the error page: "I Understand the Risks"
Let Firefox retrieve the certificate: "Add Exception" -> "Get Certificate".
*Click the "View..." button and inspect the certificate and check who is the issuer of the certificate.
You can see more Details like intermediate certificates that are used in the Details pane.
If <b>"I Understand the Risks"</b> is missing then this page may be opened in an (i)frame and in that case try the right-click context menu and use "This Frame: Open Frame in New Tab".
*Note that some firewalls monitor (secure) connections and that programs like Sendori or FiddlerRoot can intercept connections and send their own certificate instead of the website's certificate.
*Note that it is not recommended to add a permanent exception in cases like this, so only use it to inspect the certificate.

I changed my wheel group properties to no access at top disk level. I messed up, how can I change back in single user mode "command s" as I am now in Thailand and not able to access startup disks?

I messed up, I changed my "Wheel group" properties to No Access ( or something other than the default) at the top level of my startup disk "Macintosh HD".   Now my computer won't start up, I just get the spinning wheel of death.    I also am in Thailand right now, so I cannot go to a Genius at an apple store, nor do I have startup disks available.
So I was hoping there was a way to change back the properties of my disk (Volume) in single user mode (via Command +s) during startup, i.e. can I do a chmod command on the Macintosh HD listing under the Volume Directory.    Or where do i fix this?   Is it fixable without startup disks, etc...
THANKS FOR ANY HELP!!!!
If you could also please let me know you have an answer, I WOULD REALLY APPRECIATE IT!!!
thanks so much
mark
<Edited by Host>

Thomas,
Thanks for the info on command-R, didn't know about that!!!
Yes I changed the sharing "Wheel Group" permissions on my hard drive via Get Info.    But that's all I did.    And then most of the apps wouldn't respond with anything.    So not knowing I did something stupid, I decided to re-boot, and then nothing but the Wheel of Death at startup.
I was trying to limit access to my computer on this network, changed my public folder settings, and then I thought why not the whole hard drive, but at that time I had no idea what the "Wheel Group" was... so I shouldn't have touched it, BUT IT DID ...... argggggg....
I managed to go to an internet cafe & research the problem yesterday.    I used the command +s single mode to get in, and then did the necessary steps to mount the drive so I could make changes.   I basically did this:
Boot into single-user mode (boot while holding down CMD-S)
Follow the on-screen instructions to mount the file system as read-write (a fsck command followed by a mount command)
Type the following: "chmod o+r /" followed by "chmod o+x /"
Type "exit" to leave single user mode and complete the boot sequence.
I found it at this link http://forums.macrumors.com/showthread.php?t=416180
It worked... thank God!!!   Well so far so good.
I was going to try my own fix by chmod on the Hard drive listed under Volumes directory, but that doesn't seem to match the info under Get Info Window.    So I just used the fix above.    I probably should now go and do "Disk Utility - repair permissions", however I am a little gun shy right now, so I will probably wait until I am back in the States so I can go to an Apple store if it messes up.   Right now I'm following the "if it ain't broke, don't fix it" MOTTO...
So Thomas I just wanted to say THANKS for replying so quickly, and I really appreciate your help!!!
(yes I know I shouldn't have used my email addresses, but I WAS DESPERATE, but that's still no excuse)
Hopefully maybe this thread will help someone else out in the future....
Okay, thanks again!
Mark

Freezing with blue screen & can't boot from single user mode or disk

My keyboard is wired and plugged directly into my Intel iMac running OSX 10.5.8. I do not have the Leopard disks, but I do have the Tiger disks. I was trying to boot in single-user mode so that I could run AppleJack to try to fix another issue I'm having--I get the light blue startup screen flashed at me several times daily for the past week or so. When the blue screen flashes, it totally freezes my computer (obviously) and lasts from 1-10 seconds. I can't find anything that is triggering it. I haven't installed anything new that I'm aware of, and it happens whether the computer has previously been slept or not. I'm also not using an external display / additional monitor.
Also, for anyone who is nice enough to answer, please explain everything--I'm not an expert user.

Well since it is so time consuming and a security risk to turn off FileVault, I was hoping to hear from someone with more experience if this was the solution, or just something to "try"? Are you speaking from experience or just making a suggestion, leroydouglas? Thanks.

Ibook left hanging! Got info from single user mode - can u translate?

Hi, am panicking here so help really appreciated!
Got my ibook, G3, 17" screen. It won't start up. It goes as far as the spinning circle of lines. Tried to get into single user mode (got Applejack there) but it ends up saying 'we are hanging here'.
The lines previous to that include the following (don't know if any of this is useful as don't really understand it):
nfs_mountroot failed: 9
nfsboot: ntworking not initialised
panic (cpu0): nfsbootinit failed with 6
latest stock backtrace for cpu0:
backtrace:...lots of numbers here...
Proceeding back via exception chain:
exception state:....lots of numbers here...
Kernal Version:
Darwin kernal version 7.90
dates and release info here.....
No debugger configured - dumping debug information
MSR=00001030
latest backtrace for cpu0:
Backtrace:...
...and then it repeats most of that again until it says:
panic: we are hanging here
and I can't type anything. The cursor just sits.
Have also tried disk utility when booted from cd. It tries to verify the disk but says:
Catalog file entry not found for extent.
The volume needs to be repaired.
Volume check failed.
Error: the underlying task reported failure on exit (-9972)
1 volume checked
0 HFS volumes verified
1 volume failed verification
And it says the same when I try and repair the disk. Do I need to erase the disk? I do back up regularly onto zip disks.
Tried to reinstall system software but when you are prompted for a place to install it onto, there are no disks shown!
How bad is it????
nikki
ibook G3, 700mhz Mac OS X (10.3.9)
ibook G3, 700mhz Mac OS X (10.3.9)

Hi, Nikki.
What happens if you try to start up in Safe Mode? This will take awhile longer than a normal startup because it does a file check and repair of the hard disk.
If this works you will see your normal desktop. Once completely started up, try to restart normally, and go to Applications/Utilities/Disk Utility and repair permissions on the hard drive.
Here are some links on kernel panics and what to do about them:
http://www.thexlab.com/faqs/kernelpanics.html
http://www.macmaps.com/kernelpanic.html
http://discussions.apple.com/thread.jspa?messageID=607531&#607531
http://docs.info.apple.com/article.html?artnum=106805
Hope something there helps.

Reset Permissions from Single-User Mode

I believe I have accidently removed the permissions from my iMac. I can access single-user mode and need desperately for someone to walk me through how to reset the permissions (I get a blue screen when I try to boot). Please help.

JMT001 wrote:
I believe I have accidently removed the permissions from my iMac.
what do you mean? what EXACTLY did you do? did you change permissions on the top level of the hard drive to no access?
if so see this link
http://discussions.apple.com/message.jspa?messageID=2087835
if it's something else explain what you've done.

Data back up from Single User Mode

Hello,
I have a problem with my 700 MHz iBook, dual USB, with OS X 10.3.9.
Unfortunately the OS doesn't start up because of "overlapped extent allocation" problem...
I would like to re-install the complete OS but before doing it, I would like to back up some directories.
Is it possible to save some data, by connecting an Ipod or some sort of external peripheral, from the Single User mode?
If yes, how can I do it?
Thank you in advance from your kind support.

Before giving up the ghost check out these:
http://docs.info.apple.com/article.html?artnum=25770.
Manually fix Overlapped Extent Allocation Errors without Disk Warrior
Overlapped overlapped extent allocation errors can be the bane of any Mac user's existence. Often, these errors go unnoticed until the problem becomes visible: your Mac might refuse to boot, crash unexpected, or worse, critical data might disappear from the Finder. Disk Utility can detect, but not fix overlapped extent allocation errors, and certain third-party utilities, such as Alsoft Diskwarrior, can fix them, but generally without reporting the consequences.
Overlapped extent allocation error occur when the file system thinks that two files are occupying the same area on the hard disk, hence overlapping on the same "inode," which is the structure which holds the location of the data blocks the file occupies, and also file permissions and flags.
Clearing the "overlapped" or "overallocated" extent allocation essentially means that you'll have to lose some data, because the only way to remove the overlap is to delete the file that's occupying the inode. So, if you suspect, or find out, that the guilty file is a critical system file that resides in one of the hidden system directories such as /etc /var /usr/ or visible system directories such as /System or /Library, and you don't want to reinstall the whole OS (which might not fix the overlapped extent allocation anyway), it's good to have another disk available to copy the files back to your original disk if necessary: a second bootable hard drive or a firewire drive connected to your Mac when you remove the misbehaving file. Just make sure that when you copy the file back to your boot disk that the permissions are correct, so it's best to use the "ditto" command, so that all sticky bits, flags, and permissions are preserved.
In case you didn't know, you don't have to boot from an install CD in order to check for overlapped extent allocations. All you need to do is restart your Mac, while holding down command + S to boot in "single-user mode."
At the command prompt that appears, type:
$ fsck -fy
If you have an overlapped extent allocation, you'll see:
"Overlapped Extent Allocation" (File 123456d)
No matter how many times you run fsck -fy, you'll never be rid of the error.
So, simply issue the following command:
find / -inum 123456 -print
Note the "d" was dropped, or any extra letter that appears after the inode number.
The find will return a file name that matches with the inode number, and the path to that file. If you remove the file then the fsck will not return this error next time you run it.
However, before you can delete the file(s) in single-user mode, you'll need to mount the file system. Type:
$ mount -uw /
When done, issue the "sync" command, and that will flush the write cache so that all pending writes are written from memory to the disk. Also, since most OS X 10.3 Macs use the HFS+ Journaled file system, it might be a good idea to disable the journal before booting into single-user mode by typing:
$ sudo diskutil disableJournal /
then re-enable it when done fixing the overlapped extents and rebooting normally:
$ sudo diskutil enableJournal /
Chris Anderson is a long-time Linux propellerhead who just got his first Mac, an ibook G4, and can't keep his hands off of it. He currently works as a "The Architect" and general visionary for a maker of world-class collectibles.
If you own Disk Warrior then it should be able to repair a drive with overlapped extents.
There are two backup utilities included in Unix - psync and rsync. You will find them in the /usr/bin/ directory. For documentation simply enter: man psync or man rsync. In order to write data while in single-user mode you need to issue the command: /sbin/mount/ -uw / (Note: there is a "space" between the "uw" and the "/".) To mount an external drive you will need to provide the mountpoint for it in place of the "/", e.g., "/Volumes/volname") without the quotes.

How to mount USB & CDROM drives from single user mode - Solaris boot disk?

Hi All,
I need to carry out ufsrestore on a single newly replaced system disk (no redundancy / mirroring) from either USB or CDROM drives from the following steps:
( i ) GRUB => e, e, cdrom –s, Enter, b (boot from Solaris 10 x86 media).
( ii ) Choose menu 1 for Install Solaris Interactive Mode to reach single user mode.Below are the commands that I have tried in single user mode without success:
mount –r –F pcfs /dev/dsk/c1t0d0p0 /cdrom (after unmount Solaris CD)
mount: /dev/dsk/c1t0d0p0 is not a DOS filesystem.
svcadm –v enable smserver
svcadm: Pattern ‘smserver’ doesn’t match any instances
svcadm enable autofs
svcadm: Pattern ‘autofs’ doesn’t match any instances
devfsadm
devfsadm: mkdir failed for /dev 0s1ed: Read-only file system
mkdir /mnt
mkdir: Failed to make directory “/mnt”; Read-only file systemPart of the problem is due to the current READ ONLY filesystems which does not allow the creation of mount point such as /mnt.
I have been able to create both / root (/dev/dsk/c1t0d0s0) and /export/home (/dev/dsk/c1t0d0s0) filesystems with newfs that are awaiting for restore using ufsrestore.
The only option I am left with is to attach a secondary disk to install Solaris 10 on either of them before bring the system to multi-user mode so that service such as volmgt, autofs, volfs are available to access USB & CDROM drives.
Any suggestion on how to resolve this issue?
Many thanks,
Jack

Hi JKGN,
Is the directory a located under the root filesystem. ie /a? Are there any other mount point for say USB drive as well? I am not in a position to try it out right now but will get back
to you soon on whether /a exist or not.
Btw, the last thing I managed to do on this system at the time was added a secondary 1TB internal disk with the intention to restore both / and /export/home data onto this disk while
making use of all the disk device management services such as the following services only available in a fully installed Solaris system (both single & multi-user modes) installed on the
primary disk:
# svcs smserver
STATE          STIME    FMRI
online         Jun_08   svc:/network/rpc/smserver:default
# svcs autofs
STATE          STIME    FMRI
online         Jun_08   svc:/system/filesystem/autofs:default
# devfsadm
# iostat -En
c1t0d0           Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: ATA      Product: SAMSUNG HD321KJ Revision: 0-11 Serial No:
Size: 320.07GB <320072932864 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 41 Predictive Failure Analysis: 0
c0t0d0           Soft Errors: 0 Hard Errors: 5 Transport Errors: 0
Vendor: PHILIPS Product: DVD+-RW DVD8801 Revision: AD21 Serial
Size: 17.54GB <17538875392 bytes>
Media Error: 0 Device Not Ready: 5 No Device: 0 Recoverable: 0
Illegal Request: 10 Predictive Failure Analysis: 0
c2t0d0           Soft Errors: 0 Hard Errors: 0 Transport Errors: 0
Vendor: JetFlash Product: Transcend 16GB   Revision: 1100 Serial No:
Size: 0.00GB <0 bytes>
Media Error: 0 Device Not Ready: 0 No Device: 0 Recoverable: 0
Illegal Request: 7 Predictive Failure Analysis: 0
# rmformat
Looking for devices...
     1. Volmgt Node: /vol/dev/aliases/cdrom0
        Logical Node: /dev/rdsk/c0t0d0s2
        Physical Node: /pci@0,0/pci-ide@1f,1/ide@0/sd@0,0
        Connected Device: PHILIPS DVD+-RW DVD8801 AD21
        Device Type: DVD Reader/WriterHowever, I was disappointed that "iostat -En" has not found the secondary disk (1 TB) even though it was available earlier, for Solaris installation as the only disk on the same system.
As a result, I am left with no option but the need to rebuild this system with only a single primary disk while in single user mode. However, the single user mode that I am in is the
one from Solaris installation disk with restrictive (_cannot create folder for mount point or running disk management utilities_) capability such as those services just covered, compared to one from a completed Solaris installation system with full access to all filesystems and utilities / commands in general.
I would very much value your assistance on how to mount both CD & USB in this restrictive limited Read Only OS (assume that it is running from memory) in order to get complete access to
the blank primary disk so that full restore with ufsrestore could take place.
Thanks in advance,
Jack
Edited by: 797805 on 9/06/2012 04:15

How do change boot disk from single user mode?

My G5 hangs when booting at the blue screen while "Loading printing services...". Attempting to boot into safe mode only hangs at the grey gear screen. It will, however, successfully boot into single user mode. I've run fsck but no change in bootability. I have another disk in the machine that has Tiger on it. How do I change the boot disk from the single user prompt?

You can hold c and boot off the installer disk and select disk utility repair disk/permissions
or you can hold option to boot off Mac OS X on another drive, like a clone and run Data Rescue to recvoer your files.
It does sound bad, you can try going through these
http://docs.info.apple.com/article.html?artnum=106464
But I think you'll need a fresh install, hopefully you have been backing up/cloning to a external drive.
http://homepage.mac.com/hogfish/Personal11.html

Proper procedure for patching from Single User mode

Typically when I install a patch cluster from Sun, I do a sanity reboot from the console of the server using:
shutdown -y -g0 -i6
When the system comes back online, I log into the console again and then do:
shutdown -y -g0 -i0 (to go into OBP)
then
boot -s (to go into single user mode)
The procedure above was given to me from a Sun technician.
Then I install the patch cluster and reboot. It has come to my attention that Sun recommends breaking any mirrors between your disks before patching. I wanted to know what is the best way to do this for both Veritas Volume Manager and Solaris Volume Manager. For Veritas Volume Manager, I was thinking of going into the vxdiskadm menu driven utility and choosing the option to "Remove a disk for replacement" for the rootmirror disk and then after a reboot to check that the patches did not cause a problem, go back into vxdiskadm and choose the option "Replace a failed or removed disk" and select the rootmirror which should then begin to automatically resync itself to the primary rootdisk. Any comments on if this is a proper way to do this or if someone has a better method, I would love to hear it. I am assuming a system with just two internal disks: c1t0d0s2 and c1t1d0s2
Also, if anyone can comment on how to do this with Solaris Volume Manager or if it is required would be great also.
Thanks much for any advice.

Typically when I install a patch cluster from Sun, I
do a sanity reboot from the console of the server
using:
shutdown -y -g0 -i6
When the system comes back online, I log into the
console again and then do:
shutdown -y -g0 -i0 (to go into OBP)
then
boot -s (to go into single user mode)
The procedure above was given to me from a Sun
technician.Not a bad thing to check reboot before patching, but I don't think it's in any official documentation that I'm aware of.
Then I install the patch cluster and reboot. It has
come to my attention that Sun recommends breaking any
mirrors between your disks before patching.Again, I don't know if it's "official", but if you have a backup copy that you could boot from, it does reduce the possibilities of critical problems from a bad patch.
I wanted
to know what is the best way to do this for both
Veritas Volume Manager and Solaris Volume Manager.
For Veritas Volume Manager, I was thinking of going
into the vxdiskadm menu driven utility and choosing
the option to "Remove a disk for replacement" for the
rootmirror disk and then after a reboot to check that
the patches did not cause a problem, go back into
vxdiskadm and choose the option "Replace a failed or
removed disk" and select the rootmirror which should
then begin to automatically resync itself to the
primary rootdisk. Any comments on if this is a proper
way to do this or if someone has a better method, I
would love to hear it. I am assuming a system with
just two internal disks: c1t0d0s2 and c1t1d0s2
Also, if anyone can comment on how to do this with
Solaris Volume Manager or if it is required would be
great also.Well, it'll work as you've described, but what if the patches fail? The disconnected mirror is not bootable. You'd have to go through an unencapsulation and other things from a CD.
I've often simply pulled one side of the mirror while the machine was shutdown. Since the mirror was valid prior to pulling, it will boot. If there's a problem, I shut down, swap disks, and boot from the untouched mirror. If no problem, I re-insert, reattach the disk to the diskgroup, then recover the volumes.
I don't know of any nice supported method of booting from an offline VxVM mirror that doesn't involve a very long series of steps. My method isn't supported, but it does work. If you have both disks in the machine at the same time though, it'll update the private regions. Don't do that until you're ready to sync up one way or the other. Test before doing it in production.
In any event, you should have a backup ready to go.
Darren

Backupping from single-user mode

I am currently only able to use the single-user mode, and am looking for possibilities to take some backup of certain files before I venture reinstalling or something.
Is it possible to write to disk from S-U mode? How?
Can I do it in another way, e.g. create a new partition? How?
I need to be enlightened

Yes, I used the install CD. Verification said my disk was OK. There were some inconsistencies with permissions, so I repaired those, but my problem still persists (se thread "Authentication error???"), so I am still interested in backupping before I try Archive & install or something.

Can I access Terminal from Single User Mode?

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